As described in a Patent Document (International Publication No. WO 2005/110726 Pamphlet), a conventionally known rotary powder compression molding machine used for production of tablets includes a spray nozzle that sprays a powder lubricant so as to allow the powder lubricant to adhere to a punch and/or an inside of a die. In the rotary powder compression molding machine described in the Patent Document, the powder lubricant sprayed from the spray nozzle is charged electrostatically and differently so as to adhere to each of an upper punch, a lower punch and the die.
The spray nozzle for the powder lubricant has a concave portion formed of three-dimensional curved surface and an electrode projecting into the concave portion. The powder lubricant is supplied into the concave portion using a pressurized gas and is electrostatically charged in the concave portion by a direct voltage that is applied to the electrode then to be guided toward the upper punch or the like along the three-dimensional curved surface of the concave portion.
However, in such a configuration, the powder lubricant possibly adheres to regions other than a target region, resulting in deterioration in efficiency of the powder lubricant. Specifically, the powder lubricant is sprayed along the three-dimensional curved surface in the nozzle provided with the concave portion described above, so that the powder lubricant scatters into a relatively large area. Therefore, increased is a quantity of the powder lubricant which is sprayed but does not adhere to the target region, that is, which does not contribute to product molding, resulting in deterioration in efficiency of the powder lubricant.